Another approach uses silicon's ability to stabilize β-carbocations (β-effect).
In addition, the TMS group behaves like a proton and is removed after
nucleophilic activation:

S. E. Denmark, T. K. Jones, J. Am. Chem. Soc., 1982, 104, 2642.

A limiting factor is also the stereoselectivity. As the substituents α to the
keto group are prone to racemization
using strong Lewis or Brønstedt acids due to equilibria involving proton transfer,
the diastereoselectivity is often low:

A more detailed look at the mode of the cyclization reveals that 4 π electrons are involved in a conrotatory mechanism, but any diastereoselectivity
involving the new formed σ bond is lost after elimination of the proton:

The Nazarov Cyclization is a rare example of a Lewis acid-catalyzed 4-π
conrotatory electrocyclic reaction. Asymmetric induction could be achieved if a
chiral Lewis acid were able to control the direction of the conrotatory closure.
However, only a few such reactions have been reported. Common drawbacks are low
enantioselectivity and the use of nearly stoichiometric amounts of the chiral
Lewis acids, which must still be overcome.